Crate dryoc[−][src]

dryoc: Don’t Roll Your Own Crypto™1

dryoc is a pure-Rust, general-purpose cryptography library. It’s also an implementation of libsodium, and designed to be 100% compatible with, and interchangeable with, libsodium’s API.

Doing cryptography properly is hard. While no human is infallible, computers are pretty good at following instructions. Humans are bad at following instructions, but they do a decent job of giving instructions, provided they can effectively communicate intent. Thus, if the instructions humans give the computer are correct, we can be reasonably assured that the operations the computer does are correct too.

This library tries to make it easy to give the computer the correct instructions, and it does so by providing well-known implementations of general-purpose cryptography functions, in an API that’s relatively easy to use, type safe, and hard to use incorrectly.

As the name of this library implies, one should avoid trying to “roll their own crypto”, as it often results in avoidable mistakes. In the context of cryptography, mistakes can be very costly.

The minimum supported Rust version (MSRV) for this crate is Rust 1.51 or newer.

Features

  • 100% pure Rust
  • mostly free of unsafe code2
  • free of corporate and governmental influence
  • automatic safety features such as zeroization of data structures (via Drop and Zeroize)
  • protected memory support, with an API designed such that it’s hard to accidentally unprotect your memory
  • designed to be especially difficult to use incorrectly3
  • provides compatibility with libsodium, and implements most of its core functions
  • covers common use cases for safe encryption, hashing, and message authentication
  • available under the LGPL3 license

APIs

This library includes both a Classic API, which is very similar to the original libsodium API, and Rustaceous API with Rust-specific features. Both APIs can be used together interchangeably, according to your preferences. The Rustaceous API is a wrapper around the underlying classic API.

It’s recommended that you use the Rustaceous API unless you have strong feelings about using the Classic API. The Classic API includes some pitfalls and traps that are also present in the original libsodium API, and unless you’re extra careful you could make mistakes. With the Rustaceous API, it’s harder to make mistakes thanks to strict type and safety features.

FeatureRustaceous APIClassic APILibsodium Docs
Public-key authenticated boxesDryocBoxcrypto_boxLink
Secret-key authenticated boxesDryocSecretBoxcrypto_secretboxLink
Streaming encryptionDryocStreamcrypto_secretstream_xchacha20poly1305Link
Generic hashingGenericHashcrypto_generichashLink
One-time authenticationOnetimeAuthcrypto_onetimeauthLink
Key derivationKdfcrypto_kdfLink
Key exchangeSessioncrypto_kxLink
Public-key signaturesSigningKeyPaircrypto_signLink
Protected memory4protectedN/ALink

Using Serde

This crate includes optional Serde support which can be enabled with the serde feature flag. When enabled, the Serialize and Deserialize traits are provided for data structures.

Security notes

This crate has not been audited by any 3rd parties. It uses well-known implementations of the underlying algorithms which have been previously verified as using constant-time operations.

With that out of the way, the deterministic nature of cryptography and extensive testing used in this crate means it’s relatively safe to use, provided the underlying algorithms remain safe. Arguably, this crate is incredibly safe (as far as cryptography libraries go) thanks to the features provided by the API of this crate, and those provided by the Rust language itself.

Acknowledgements

Big ups to the authors and contributors of NaCl and libsodium for paving the way toward better cryptography libraries.

  1. Not actually trademarked. ↩

  2. The protected memory features described in the protected mod require custom memory allocation, system calls, and pointer arithmetic, which are unsafe in Rust. ↩

  3. The Rustaceous API is designed to protect users of this library from making mistakes, however the Classic API allows one to do as one pleases. ↩

  4. Currently only available on nightly Rust, with the nightly feature flag enabled. ↩

Modules

auth

Secret-key message authentication

classic

Classic API

constants

Constant value definitions

dryocbox

Public-key authenticated encryption

dryocsecretbox

Secret-key authenticated encryption

dryocstream

Encrypted streams

generichash

Generic hashing

kdf

Key derivation functions

keypair

Public/secret keypair tools

kx

Key exchange functions

onetimeauth

One-time authentication

protectednightly

Memory protection utilities

rng

Random number generation utilities

sha512

SHA-512 hash algorithm

sign

Public-key signatures

types

Base type definitions

utils

Various utility functions